Spatially multiplexing in wireless communication systems involves multiple source devices simultaneously transmitting different signals in a common frequency channel to the same destination device. For example, multiple wireless mobile stations may be configured to simultaneously transmit, in the same channel, signals to a wireless base station. The wireless base station has multiple antennas on which it can receive the multiple transmissions from the multiple mobile stations. Spatial multiplexing takes advantage of the fact that there are multiple “spatial channels” between the source devices and the destination device. The spatial channels differ in their spatial signatures, but are substantially the same in frequency and time.
Collaborative spatial multiplexing is a form of spatial multiplexing where multiple spatial channels are generated through collaboration among a plurality of source devices. That is, the source devices are identified and commanded or configured to transmit at the same time (and in the same frequency channel) to the same destination device. Collaborative spatial multiplexing offers the ability to increase the capacity of a system in one direction, e.g., on uplinks from multiple wireless mobile stations to a base station. However, the challenge in designing systems with collaborative spatial multiplexing capabilities is to be able to adequately recover the data contained in each of the transmissions from the respective source devices.